Assimilation happened a long long long time ago. Even in the Mob's hey-day which people argue about when that exactly was, but even in that pre-appalachin time it wasn't some honorable lets-do-it-for-Italy kind of thing. It was about money and survival. Always has been always will be.

ties to the old country have a lot to do with the house your brought up in. if u still have family there (a lot dont), things like that. Tons of italian americans have zero ties to Italy/Sicily, not just this generation but previous generations as well.

If anything the 'decline in ranks' has more to do with gentrification and suburbanization. Even though the tri-state and basically the whole north east has a ton of italian americans, there are no real enclaves anymore as their used to be. rightfully so though. everywhere is accessible due to better public transport and cars. you dont need to spend your life on the 6th floor of a 250 year old decrepit walk-up on Elizabeth street if you have the money to go out to Long Island and have a yard and all that.

Theres always gonna be italian americans, and there's always gonna be kids wanting to make a quick buck who just can't live legit. the mob will always be around in New York.